Typically, electronic devices include one or more camera modules for providing enhanced media functionality. For example, the typical electronic device may utilize the camera modules for photo capturing and video teleconferencing. In the typical electronic device with multiple camera modules, the primary camera module has a high pixel density and an adjustable focus lens system while the secondary camera module is front-facing and has a lower pixel density. Also, the secondary camera module may have a fixed focus lens system.
In typical electronic devices, the secondary camera module may comprise a reflowable camera module. Although the reflowable camera module is less costly and readily installed, for example, via surface mount connectors, the reflowable camera module may be relatively fragile to assemble during manufacturing.
For example, U.S. Patent Application No. 2009/0057544 to Brodie et al, assigned to the present application's assignee, discloses a camera module for a mobile device. The camera module comprises a lens, a housing carrying the lens, and a lens cap over the lens and housing. The camera module includes a barrel mechanism for adjusting the lens.
Referring to FIGS. 1-2, a typical camera module 10 is described. For example, this camera module 10 is available from STMicroelectronics of Geneva, Switzerland as part no. VS6559. The camera module 10 includes a housing 12, a glass layer 16 in the housing, an image sensor integrated circuit (IC) 25 embedded in a through silicon via (TSV) substrate 27 below the glass layer, a plurality of lenses 14-15 stacked together in the housing, and a plurality of spacers 17-18 adjacent the lenses and the glass layer. The camera module 10 includes a cap 11 over the lenses 14-15, and a plurality of adhesive joints 19-21 for securing adjacent components in the camera module 10. The reflowable camera module 10 includes a plurality of bump contacts 22a-22d on a backside of the TSV substrate 27. Typically during manufacture, the camera module 10 is stacked in sandwich like manner. During these stacking steps, the adhesive joints 19-21 are formed. A potential drawback to this approach of manufacture is that the layers of the stack can be detached if there is a weak adhesive joint.